The numbers should be matched, or you will have tracking problems.
Yes it makes a difference which way the links are positioned, the longer holes should be on the bottom.
Only 1 swash plate on the CX, don't know how you would get 2, unless they seperated, if they did seperate, then you should get a replacement.

Thanks for quick response!

One thing though about Lower Sp! In my owners manual for Cx it shows part number 018 as lower SP. Part number 016 as Upper Sp! So according to manual they are seprate parts and on my CX they are seperate! I found a question about this earlier and the guy actually took a picture of Upp and Lower seperated. He was basicly asking same question but no one responded!
I need to get with Horizon Hobby on blades though because several of my lower blades are unreadable.

I called Horizon Hobby and the Tech. said as long as blades come from same pack, matching numbers doesnt matter! That is good becuase I cant make out numbers anyway

Regardless of what the book calls it, there is only 1 swashplate on the CX, CX2, CP, CPpro, T-Rex, MX450 etc etc etc, in fact the only heli I can think of that has 2 swashplates is a CH56 Chinook heli, and it has 2 seperate rotors, one in the front and one in the rear. E-Flite might be referring to the ROTOR heads, there are 2 of those 1 upper and 1 lower.